Thermal conversion and epitaxial overgrowth of nanopores etched in InP and GaAs

Both crystallographically oriented and current line oriented pore networks in InP and GaAs are created by electrochemical dissolution. Heat treatment of InP pores at 650°C and of GaAs pores at 700–850°C converts them into microcavities maintaining almost the same crystallographic direction. As a transition between micro/nanopores and micro cavities the lamellar structures are obtained. Mass transport is responsible for the pore conversion. The effect of 'anion' vapour pressure is proved to be crucial for the microcavity formation since it influences the mass transport during the heat treatment. Electron microscopy and photoluminescence experiments reveal the absence of significant extended defects, both after the formation of pores and cavities. The capability of improved structural quality of homo– and hetero–epitaxially overgrown films on porous InP is demonstrated by liquid phase epitaxy growth of InP and InAs. Overgrowth of the porous GaAs substrates by ternary GaInAs layers with different lattice mismatch was realised by metal organic vapour phase epitaxy.

Most popular related searches

Related articles

In order to prevent health risk from potential exposures to phthalates, a glow discharge plasma (GDP) process was applied for phthalate degradation in aqueous solution. The results revealed that the phthalate derivatives 4-hydroxyphthalic acid, 4-methylphthalic acid and 4-tert-butylphthalic anhydride could be degraded efficiently in GDP process (498 V, 0.2 A) with high removal efficiencies of over 99% in 60 minutes. Additionally, pyrite as a promising heterogeneous iron source in the Fenton reaction was found to...

A systematic study combining batch experiments with spectroscopic analyses was carried out to better understand the effects of various organic acids on pyrite dissolution and subsequent Cr(VI) removal in aqueous systems. Our results suggest that organic acids had no effect on total Fe dissolution from pyrite relative to systems containing no acid. However, while nearly 100% of total Fe dissolved from pyrite was in Fe(II) form in the absence of ligands, the addition of organic acids led to significant oxidation of...

Multivariate statistical methods – principal component analysis (PCA) and hierarchical cluster analysis (HCA) – are applied to identify geochemically distinct groundwater groups in the territory of Latvia. The main processes observed to be responsible for groundwater chemical composition are carbonate and gypsum dissolution, fresh and saltwater mixing and ion exchange. On the basis of major ion concentrations, eight clusters (C1–C8) are identified. C6 is interpreted as recharge water not in equilibrium with most...

The rising potential for the release of engineered nanoparticles (ENPs) into aquatic environments requires evaluation of risks in order to protect ecological health. The present review examined knowledge pertaining the interactions of metal‐based ENPs with aquatic higher plants, identified information gaps and raised considerations for future research to advance knowledge on the subject. The discussion focused on ENPs' (i) bioaccessibility; (ii) uptake, adsorption, translocation and bioaccumulation, and (iii)...